Manuscript Summary: This codex consists mainly of copies of letters written by the church father Augustine († 430), produced in the second half of the 9th century, possibly in Mainz. A small section at the front and some pages at the end, however, were produced in the 11th century, during the tenure of Ekkehart IV († um 1060), in the Cloister of St. Gall; these sections contain a Latin version of the Old High German "Galluslied" (originally written by the St. St. Gall monk Ratpert), translated by Ekkehart IV, and various excerpts of mathematical and astronomical content. (smu)